This invention relates to portable data storage cartridges, and, more particularly, to openable and closable covers for access openings in such portable data storage cartridges.
Portable data storage cartridges provide convenient means for storing data which may be transported between uses. One example comprises automated data storage libraries which can contain large quantities of portable data storage cartridges on storage shelves and employ robot accessors to access a cartridge when needed and deliver the cartridge to a data storage drive or transfer station.
An opening is provided in an exterior housing for such cartridges to allow access to the data. In the example of a data storage device housed in a portable data storage cartridge, such as discussed in the incorporated U.S. patent application Ser. No. 09/842,030, an opening is provided such that electrical contacts of an external interface within the cartridge may be engaged by a matching connector of a transfer station. In the example of a magnetic tape, an access opening is provided either for withdrawal of a portion of the magnetic tape, or for insertion of a read/write mechanism of a data storage drive into the cartridge.
When not in use, the cartridges are typically transported for storage away from the transfer station or data storage drive, for example, in storage shelves, and are exposed to potential contamination. Hence, a door is typically provided to cover the access opening when the cartridge is not in use. One example of a covering door and dust cover is illustrated in U.S. Pat. No. 4,897,751, which is pivoted from an access opening on one edge of a cartridge to a position exterior to the cartridge on an adjacent top side of the cartridge. Such a pivoting door arrangement requires excessive space exterior to the cartridge to accommodate the door and dust cover. A similar example is illustrated in U.S. Pat. No. 4,093,149, in which two adjacent doors are pivoted from one edge of a cartridge in opposite directions outwardly to extend both in front of the edge of the cartridge and to the adjacent edges of the cartridge, requiring a great amount of space exterior to the cartridge to accommodate the doors.
The need to reduce the external space requirement was recognized in U.S. Pat. No. 6,111,725, which employs a multiple panel hinged door. One panel is located on the top of the cartridge and is arranged to slide along the top. The other panel is at the front of the cartridge, which has a track at each side of the door opening and in which spindles of the front panel ride. The tracks are curved up and toward the rear of the cartridge, such that, when the top panel is pushed toward the rear of the cartridge, the front panel is tilted to the rear of the cartridge, and the bottom of the front panel rides up the tracks toward the top and rear of the cartridge. A linear spring attached to the top of the top panel pulls the top panel toward the front so that the top panel pushes the front panel along the track into the closed position. Although saving space outside of the cartridge, substantial space is required within the cartridge so that the front panel can tilt inwardly and follow the track. Further, the friction of the tracks may interfere with smooth operation of the mechanism. Still further, a high degree of precision is required to insure that tolerances between the pieces do not allow the front panel to become skewed and jammed, especially when being pushed by the top panel.
In addition to the desire to avoid excessive use of space exterior to the cartridge as discussed above, it may be advantageous to avoid excessive use of space within the cartridge, since the number of cartridges vastly exceeds the number of drives and transfer stations.
Hence, it is an object of the present invention to provide a means for opening and closing an access opening of a portable data storage cartridge which, in operation, has a space requirement which is small as compared to the total volume of the cartridge.
Another object of the present invention is to provide a means for opening and closing an access opening of a portable data storage cartridge which has low friction and has a reduced requirement for precision.
A shutter mechanism of a portable data storage cartridge is provided at an access opening in an exterior housing of a portable data storage cartridge.
First and second clamshell shutters are arranged to meet and form a common junction; each clamshell shutter having a pivot axis substantially parallel to the common junction. First and second sets of actuation paddles are positioned respectively at the first and second clamshell shutters, and, in one embodiment, are formed in common with the respective first and second clamshell shutters. The actuation paddles are arranged to, when engaged by actuation pins, pivot the respective clamshell shutters in opposite directions away from the common junction.
First and second sets of pivot supports are mounted within the portable data storage cartridge. Each set of pivot supports mounts the pivot axis of one of the clamshell shutters such that the pivot axes are parallel to one another, such that the common junction is positioned at the access opening of the exterior housing, such that, when pivoted away from the common junction by the engaged actuation paddles to expose the access opening, each clamshell shutter remains within the exterior housing. In one embodiment, the pivot supports comprise trunion bearings which are positioned such that pivots forming the pivot axes of the first and second clamshell shutters are closely adjacent and separated.
Springs are arranged to urge the first and second clamshell shutters about the respective pivot axis toward the common junction to close the access opening.
In one embodiment, the clamshell shutters each comprises a flat surface at the common junction, which extends longitudinally along the common junction, and the flat surface faces outwardly at the access opening, such that an opposed edge of each of the flat surfaces forms the common junction.
In one embodiment, the clamshell shutters each comprises a section of a peripheral surface of a right cylinder extending from the flat surface away from the common junction, and has end caps mounting the actuation paddles, thereby minimizing the use of space internal to the cartridge.
In one embodiment, the actuation paddles each comprises a camming surface for engagement by an actuation pin. The camming surfaces are of a length such that the ends thereof opposite a respective pivot axis, when engaged by the actuation pins such that the respective clamshell shutters are pivoted to a fully open position, the actuation pins move across the end thereof, thereby limiting the pivoting action.
In one embodiment, the actuation paddles each comprises a Teflon filled plastic at a camming surface thereof for engagement by one of the actuation pins. Additionally, commonly formed actuation paddles and clamshell shutters may be formed of a Teflon filled plastic.
For a fuller understanding of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings.